| Title | Cessation of Spring Flow and Spring Feed Depths, Geyser Valley, Wairakei |
|---|---|
| Authors | Paul White & Trevor Hunt |
| Year | 2001 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | |
| Abstract | Historic spring flow data show that the date of spring-flow cessation was not simply related to spring elevation. A model of the cessation of spring flows, using a reservoir pressureelevation relationship applied to spring SP18, reasonably predicts the flow cessation date for five springs (Group A) but poorly predict that for seven other springs (Group B). These two groups of springs do not appear to be clustered at the ground surface. The pressure-elevation relationship suggests that the Group A springs have a feed fiom -90 to -130 mRL and Group B springs feed fiom - 350 to -500 mRL. The spring flows therefore trace pressure variations in the geothermal reservoir in two zones. This model is consistent with the observation that the chloride in Group A springs declined at least three years earlier than that in Group B springs. |